Question: Simplify the following expression: $x = \dfrac{-20a - 8}{12}$ You can assume $a \neq 0$.
Find the greatest common factor of the numerator and denominator. The numerator can be factored: $-20a - 8 = - (2\cdot2\cdot5 \cdot a) - (2\cdot2\cdot2)$ The denominator can be factored: $12 = (2\cdot2\cdot3)$ The greatest common factor of all the terms is $4$ Factoring out $4$ gives us: $x = \dfrac{(4)(-5a - 2)}{(4)(3)}$ Dividing both the numerator and denominator by $4$ gives: $x = \dfrac{-5a - 2}{3}$